There has been a new release of Great Cow Basic.
http://gcbasic.sourceforge.net/about.html
New features have been added and support for more pic18.
http://gcbasic.sourceforge.net/chips.html
The compiler runs on windows only, and here are the install instructions
http://gcbasic.sourceforge.net/starting.html
You can write and compile your BASIC program for the pic chip, and the compiler will output an assembly language file ("myprogram.asm").
1.) Put .asm file in its own folder.
2.) Start up mplabx and make a new standalone project
3.) Select your chip from the dropdown menu.
4.) Select the assembler as your tool.
5.) Give your project a name.
6.) Browse to the folder location of the asm file.
7.) Select "finished".
8.) Right click on "Source" (in the upper left of mplabx) and add your asm file with the file browser
9.) Click Build, you should have no errors
If you build it under linux, the only error you should have will be that it can't find the .inc file. That is because the include file is spelled with capital letters and the real file is lower case. Change the letters.
Now you can blow the code into the chip.
New users of pic will really like this because the BASIC compiler handles all the tedious setup of the peripherials and other stuff for you. You will be writing programs in 20 minutes, rather than reading the datasheets for 3 hours. The library also includes LCDs and simplified access to I2C ecternal peripherials and to the internal eeprom.
Check out the online manual.
http://gcbasic.sourceforge.net/help/
Also, they have a forum.
http://sourceforge.net/p/gcbasic/discussion/
Good luck and happy piccin'.